Electric writing instrument



Nov. 15, 1949 H. RAPAPDRT ELECTRIC WRITING INSTRUMENT Filed Jan. 28, 1946 Patented Nov. 15. 1949 UNITED STATES P TENT OFFICE Application January 28,

1946, Serial No. 643,918

4 Claims. (01. 21929) The present invention relates to improvements in electric writing instruments and more particularly to instruments of the type used for making inscriptions on leather, wood or other materials which are susceptible of being marked or branded by the imprint of a hot point thereon.

An object of the invention is to provide an instrument of the character described with means for preventing overheating of the holder or body portion so that the instrument may be used without discomfort to the person using the same.

Another object is to provide a burning tool with a heat radiating element embodying means to insure maximum dissipation of heat.

Another object of the invention is to provide a holder for an electric writing instrument in which electrical terminal contacts, provided therein, are adequately protected so as to prevent inadvertent contact therewith and possible injury to the person using the instrument.

Another object is to provide an electric writing instrument with a detachable heat-radiating element, including a writing tool,

principle thereof which is considered to be the best mode contemplated for applying that principle. Other embodiments of the invention, em-

bodying the same or equivalent principle, may be view through a fragment of the writing instrusectional detail view sectional detail view The holder ll heat-resisting material substantially in the form side circumferential face with circumferentially spaced longitudinal ribs l 4 which terminate short of one end thereof. The inside face of the holder as at l5, thereof so as to provide in effect a receptacle [6 into which the heat-radiating element I2 is adapted to be inserted.

As best shown in l9 extend into the outlet socket 281 and terminate as to adhesively bind the outlet socket to the ribs and thereby prevent its displacement.

It should be evident, at this time, that the terminal contacts l9 are positioned well below the outwardly disposed end of the outlet socket 28, which in turn is located inwardly of the end of the holder II. This construction affords means whereby inadvertent contact with th terminal contacts [9 is prevented. The holder l I, and particularly the receptacle I6 provided in the end thereof, is adapted to telescopically receive the heat-radiating element 12.

Referring particularly to the detailed disclosure of the heat-radiating element in Fig. 2, said ele-- ment consists of a substantially cylindrical body 25 fashioned from ceramic or other material having relatively high electrical and heat-resisting qualities. The body 25 is provided with a plurality of axially aligned bores 26, 21 and 28 provid.

ing internal shoulders 29 and 31 at therespective junctures thereof, and the outside surface of said body is fashioned cumferentially spaced longitudinally extending radial fins 32 which serve to increase the heat radiation.

A tubular writing tool or implement 33,;closed and pointed at one end, as at 3A, is fitted within the bore 25 and extends beyond one end of the body. The inner end of said tool tat is provided with radial external lips 35 adapted to rest against the shoulder 29 to prevent withdrawal of the tool from the body 25. A heat-resistance unit 36 of any conventional construction is inserted into the tubular writing tool 33 and said heat-resistance unit is connected, as by means which of wires 31 and 38, to terminal blades 39 project outwardly from the other end of the body 25. As shown, the terminal blades 39 are each provided with an offset portion 4% adapted to rest against the shoulder 3i to limit inward movement thereof during assembly, and a plug 42 preferably fashioned from hard rubber, Bakelite, or other material having relatively high electrical resistance, is fitted over said terminal blades to retain them in their spaced apart relationship. The plug 42 has an external diameter corresponding substantially to the internal diameter of the bore 23 so as to fit snugly therein and provide a firm mounting for the terminal blades 39.

A cement 43 having high electrical resistance qualities is spread over the plug 42 to firmly bind said plug within the body and to prevent in.- aclvertent removal and subsequent displacement of the terminal blades. The interior of the body 25 defined by the intermediate bore 21 preferably is suitably filled with mica or other material having high electrical resistance qualities.

In use, the heat-radiating element l2 is telescoped into the holder receptacle i6 and when in this position the terminal blades 39 extend through the slotted openings 2! in the outlet socket 20 so as to make an electrical circuit between the heat resisting unit 36 and the source of electrical current which is supplied through the conductors H. The writing instrument is prevented irom over-heating to an objectionable degree by the presence of the internal ribs 14. and the external fins 32, it being evident that the internal ribs l4 provide ample space, as. at 44 (Fig. 3), between the inside surface of the body It andthe outlet socket 251 'to allow for the free, circulation of air through the holder H. Th fins .32 on the heat-radiating element I2 also provide passageways leading from the atmosphere into communiwith a plurality of circation with the spaces 44 and further, said fins provide spaced surfaces which afiord means whereby the instrument may be firmly grasped without discomfort to the user.

It should be quite evident, at this time, that various types of writing implements or tools 33 may be provided in heat-radiating elements of the kind shown, and that various heat-radiating elements may be mounted within the holder H easily and quickly so as to adapt the instrument to a multitude of specific uses.

Although an exemplary form of the improved electric writing instrument has been disclosed in the accompanying drawing and described in detail hereinabove, it should be: understood that the invention is capable of embodying a wide variety of modifications in detail construction without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. An electrical writing instrument comprising a tubular holder, longitudinal ribs on the inside face of said holder substantially coextensive with the length thereof but terminating short of one of its ends, an electrical outlet socket having electrical connectionswith a ourrentsource mounted firmly in said holder, said socket being of a size to it snugly within the annular space defined by theinnerfaces of said'ribs so as to provide Segmental air spaces between the socketv and the inside face of said holder,. and wheat-radiating element including a burning tool inserted into the holder over said socket, said heat-radiating element having longitudinal heat-radiating fins on itsoutside surface effective to maintain air spaces connecting the handle .interior'with. atmosphere, and a pair of terminal blades on said elementengageable in said outlet socket .toconnect theburning tool with the current source.

2. A writing instrument ofa kind to be heated electrically comprising a holder in the formof a; cylindrical body, an electrical, outlet socket mounted within said body adjacent. one end, longitudinal internalribs in'sai'dbody to hold the electrical outlet socket spaced from the. inside face of the cylindricalbody so that air may circulate freely within the holder means connecting said socket with a current source, a, heat-radiatingelement including a: writing tool having an electrical-resistance unit therein mounted in said holder end, said element having, heat-radiatin fins providing air passageways between adjacent fins leading from the interior of the holder to the atmosphere, and terminal blades-on said. e1ement electrically connected with the electricalresistance unit engageablein said outlet socket so as to complete an electric circuit between the unitand a source of electric current.

3. An electrical writing instrument comprising a tubularholder, an electricaloutlet socket having electrical connections with a current source and mounted firmly in said holder, means for locating said socket substantially axially of said holder, but providing air. spaces between said socket and .the inside surface of said holder, and a heat-radiating element, including a burning tool receivable in said holder, said heat-radiating element having longitudinal heat-radiating fins onits outside surface effective to maintain air spaces connecting theaholder. interior with the atmosphere, and a pair of terminal blades-on said element engageable in said outletsocket toconmeet the burning tool with the current source.

4. An electrical writing instrument comprising a hollow cylindrical body, an electrical socket mounted within said body adjacent one end thereof, means for locating said socket substantially axially of said body but providing air spaces inside surface of current source, a heat-radiating element including a writing tool having a l1e=at-resistance unit therein mounted in said body end, said element having heat-radiating fins providing air passageways between adjacent fins leading from the interior of the body to the atmosphere, and terin said outlet socket so as to complete an electric circuit between the unit and the source of electric current.

HERMAN RAPAPORT.

6 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

